Ion implanters are used in semiconductor fabrication to introduce impurity ions (also referred to as dopants) into semiconductor materials. The implanter generates a plasma containing the impurity ions. An electro-magnetic field accelerates the ions to an energy of 2 keV or more, so the ions implant below the surface of the semiconductor substrate.
A Hall-current ion implanter uses a heated filament or hot cathode to generate hot electrons for dissociation. The hot electrons bombard process gas molecules within a dissociation chamber, causing ionization, and released electrons continue striking other gas molecules to create more ions in a chain reaction until the ions touch the arc chamber wall.
Over time, the hot filament and cathode can oxidize and be consumed, so that vaporized tungsten atoms are sputtered. This generates byproducts and reduces the source head lifetime.